When I first started reading about compost theory (yes there are whole books on the topic), I was amused by this piece of advice often given... "It is best to build your compost pile all at once so that proper layering may be achieved." I thought this was just plain silly talk. How exactly is this "all at once" layering to be achieved. Do you only weed your garden once a year? Or mow your grass once a season? The ingredients for a compost pile are being collected daily - how is it possible to properly layer your if you don't work in the Rodale Press test garden?
Well I think I have it figured now. The multiple bin system and a commitment to periodically turning your compost allows for the all at once approach with proper layering - within the reality of daily garden work. Here is a detailed post about how I build and manage my compost along with some pictures.
I have a two bin system. In order to talk about the whole process, lets assume we are starting with two empty bins (#1). As garden season gets underway and I begin to accumulate compost ingredients, I toss them in bin #1 - I call this the green manure bin. During this early accumulation phase, I don't really bother with layering (unless it gets smelly - then I toss some dirt on top). In the heart of garden season it takes me about a month or two to fill up this green pile.
Once the green pile is full - that is when the real compost theory is put into action. I prepare to turn, aerate, and layer the green pile from bin #1 into the adjacent empty bin #2. This is a good 3 hour project, but very enjoyable. I begin by placing a 4 inch diameter black pipe with 1/2inch holes drilled in it vertically in the center of bin #2. This pipe will act as a chimney to help aerate the new pile that I am about to create. Another aeration step, and a good way to break down large debris is to layer large sticks as a foundation layer at the bottom of the bin. The purpose of these sticks is to allow for some shifting and air flow into the pile as it begins to break down, so don't lay these babies like sardines in the bottom of the pile. The more catywompus this stick layer is - the better. See photo #1 for pipe and stick layer.
Compost theory says to build your pile with alternating layers of brown ingredients (carbon) and green ingredients (nitrogen). My stick layer is certainly brown, so now it is time to add some green. I am lucky enough to own over 200 linear feet of privite surrounding my property, which needs to be clipped at least twice a year. In order to get my hands on a sufficient quantity of green materials on compost turning day, I can always clip my hedges. The green layer in photo #2 is approx 4 inches of privite hedge clippings.
Next I spread my favorite compost additive (mushroom manure) with it's high nitrogen content on top of that. You can do without the mushroom manure by adding garden dirt or previously decomposed compost. I just happen to live down the street from a mushroom manure supplier and for $14 for a truck load, I splurge. After the first couple of layers I hit the pile with a couple gallons of water. A good compost pile is a slightly moist compost pile. See photo #3.
Next, I start to bring over the partially decomposed stuff from bin #1 - I consider this stuff a brown (carbon) ingredient although who knows exactly. I am always amazed at how much the "green pile" in bin #1 has broken down in a fairly short period of time. The pile I moved over last week had lots of heat and no discernable kitchen scraps and it was only a month old. I move the bin #1 ingredients to bin #2 in approx 4 inch layers - starting at the top and working my way down. As I bring the stuff over, I chop it and mix it break it up. Then I layer it with more nitrogen. Once my pile in bin #2 is about 1/2 full I stop using "fresh green" ingredients like hedge clippings for my nitrogen layer. Instead I just use mushroom manure. Why? Because the compost that you are now moving over from bin #1 to bin #2 is pretty mature and well decomposed. It just needs a couple more weeks of burn to be ready to use in the garden. The mushroom manure is the perfect ingredient to get this stuff fired up one last time without introducing new large clumpy ingredients. See final photo.
That's my compost process. And it works pretty well. I now have about 10 cubic feet of finished compost on the top of my black gold pile in bin #2. I also have a completely empty bin #1 which I can begin to fill with my daily garden clippings. As I use the black gold and work my way down this pile, I will periodically toss various harder to decompose ingredients such as sticks, cardboard, etc over from the black side to the green side. Almost 90% of this pile will be fine to use. Once I reach the large stick layer at the bottom, it is time to start again.
I LOVE Compost!